This invention relates to apparatus for successively splicing parallelogrammatic pieces of rubber cloth, and more specifically to apparatus for joining successive pieces of rubber cloth end to end without overlap for use later in the manufacture of vehicle tires and like products.
It is customary in the tire manufacturing industry to splice a number of parallelogrammatic pieces of rubber cloth to provide an elongate strip of such rubber cloth pieces as an intermediate product. The parallelogrammatic pieces of rubber cloth are formed by cutting a continuous, selvaged strip of the rubber cloth either biaswise or crosswise, and the desired elongate strip of these rhomboidal or rectangular rubber cloth pieces is produced by successively joining their selvages. For use the elongate strip is again cut into pieces sized to suit the particular size of tires to be built.
For the manufacture of high-quality tires, it is of absolute necessity that the above described elongate strip of rubber cloth pieces be produced by evenly joining the selvages of the adjacent pieces. There are two well known methods of producing the elongate strip of rubber cloth pieces. One of the methods is herein termed "lap splice" wherein the joint is formed by overlapping the opposed edges and by forcing them against each other. The other is termed "butt splice" wherein the two opposed edges are joined without overlap. Lap splice tends to cause irregularity in thickness and/or strength at the lapped joints, which defect is substantially absent from butt splice. Generally, butt splice is far preferable to lap splice, principally from the standpoint of the provision of evenly joined rubber cloth pieces.
Butt-splicing apparatus has been known which comprises a splicer mechanism and two belt conveyors positioned forwardly and backwardly, respectively, of the splicer mechanism. Each parallelogrammatic piece of rubber cloth is fed forwardly into the splicer mechanism by one of the belt conveyors, whereas the precedingly spliced rubber cloth piece is fed backwardly into the splicer mechanism by the other belt conveyor. The rubber cloth pieces are retained in respective predetermined positions in the splicer mechanism and are then forced into end-to-end abutment against each other for butt-splicing operation.
For the correct butt-splicing of rubber cloth pieces, their opposed edges must be held exactly in parallel spaced relationship when the rubber cloth pieces are stopped in their respective predetermined positions in the splicer mechanism, and further this parallel relationship must be faithfully maintained as they are succeedingly forced into end-to-end abutment. The belt conveyors employed as feed mechanisms in the prior art butt-splicing apparatus, however, are incapable of correctly reorienting the rubber cloth pieces being fed into the splicer mechanism, due in part to the adherent and highly pliable properties of the rubber cloth. This is the principal reason why the splicer mechanism as heretofore constructed is complicated with extra means for readjusting the positions of the successively supplied rubber cloth pieces.